1. ผศ. ดร. วราวุฒิ ตั้งพสุธาดล ภาควิชาเคมี คณะวิทยาศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย varawut.t@chula.ac.th

2. Bioplastics Poly(lactic acid) Polylactide Poly(L-lactic acid) Poly-L-lacide Poly(D-lactic acid) Poly-D-lacide Other polyesters: poly(glycolic acid), poly(butylene succinate), poly(butylene adipate terephthalate), poly(ethylene terephthalate) etc. 2

3. Poly(L-lactic acid) vs Poly(D-lactic acid) 3

4. Poly(lactic acid) or polylactide 4 or polylactide

5. 5

6. Mechanism of metal catalyzed esterification 6

7. Mechanism of metal catalyzed ring-opening polymerization 7

8. Key reaction conditions for making polyesters: (that you can also play with) Temperature Vacuum (dehydration process) Catalyst Recommended paper: T. Maharana, B. Mohanty, Y.S. Negi, Progress in Polymer Science 34 (2009) 99–124 8

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10. By Worapob Kitpanitch Program of Petrochemistry and Polymer Science graduated in May 2012 10

11. Literature review 11 Benzoyl peroxide Park, E.S. et al. Journal of Applied Polymer Science, 2003, 90, 1802-1807.

12. Literature review 12 Irgacure 651 (2,2-dimethoxy-2- phenylacetophenone) UV at 365 nm Brown, C.D. et al. Journal of Biomaterials Science, Polymer Edition, 2005, 16, 189-201.

13. I.Synthesis of PLLA-diol 13 Zeng, J.B. et al. Ind. Eng. Chem. Res. 2009, 48, 1706-1711. L-lactic acid was heated to 80 °C under reduced pressure for 3 h 1.5 mol% 1,4-butanediol and 0.1 mol% TNBT were added The reaction was heated up to 160 °C under reduced pressure for 5 h and then continued at 180 °C for 5 h The resulting polymer was purified by dissolving in chloroform and precipitating in MeOH The white product of PLLA was obtained and dried by vacuum at room temperature

14. 1 H NMR spectrum of PLLA-diol 14 e f a bd c e f a c b d ppm

15. II.Methacrylated-endcapped PLLA 15

16. Effect of mole ratios (PLLA:Meth) on the degree of methacrylate substitution on PLLA chain end (reaction time = 24 h, reaction temperature = 80 °C) 16

17. 1 H NMR spectrum of PLLA-MA 17 ab ab ppm decrease

18. III.Crosslinking of PLLA 18 Thermal crosslinking The functionalized PLLA was mixed with 10 wt% BPO in chloroform The mixture was poured into a circular mold (3 mm high and 6 mm in diameter) and kept at room temperature for 24 h The mixture was heated at 150 °C for 1 h (a) (b)

19. Degree of gel content 19 Thermal crosslinking Chloroform immersion 24 h Gel content = 60%

20. By Piyachai Khomein Department of Chemistry, Faculty of Science, CU graduated in May 2012 20

21. Positively-charged PLA 21 PLAGTMACPositively-charged PLA By Piyachai Khomein Department of Chemistry

22. 22 Hydrophilicity determination of PLA+ films Sample (M n ) Degree of substitution Contact angle PLLA(2,978)- 57±2° p-PLLA(2,945)11.6 55±2° p-PLLA(2,079)23.7 56±1° p-PLLA(3,135)59.3 51±1° p-PLLA(2,029)76.5 45±4° P-PLLA(2,838)90.0 47±1° Positively-charged PLA

23. End-Functionalized PLA 23 Lu, D. D.; Yang, L. Q.; Zhou, T. H.; Lei, Z. Q., European Polymer Journal 2008, 44 (7), 2140-2145. Kobori, Y.; Iwata, T.; Doi, Y.; Abe, H., Biomacromolecules 2004, 5 (2), 530-536.

24. 24 Ouchi, T.; Kontani, T.; Ohya, Y., Polymer 44 (2003), 3927-3933 End-Functionalized PLA